Recommendation

Complete a full assessment to understand the underlying cause of the low milk supply and correct any known problems before considering domperidone.

Domperidone is the medicine of choice if medical treatment is required for low milk supply.

Use 10mg three times daily, initially for 7 days then review.

Limited evidence shows negligible amounts of domperidone pass into breast milk.

How lactation works

Lactation is complex, involving hormonal, physical, and emotional factors.

Several hormones (including prolactin, insulin and hydrocortisone) are needed for colostrum production, and for the onset of copious milk supply. For breasts to continue producing milk, the following are needed:

• a rise in prolactin levels, usually caused by nipple stimulation
• oxytocin release to allow milk ejection, caused by nipple stimulation
• regular removal of milk

Milk production is based on supply and demand. If milk isn’t removed, supply will reduce and eventually stop.

Signs of normal milk supply

Colostrum, in small volumes, is produced during the first 24 to 48 hours after birth. Larger volumes of breast milk are produced by the fifth day.

After the first two weeks of life, the best indicator of adequate milk supply is the baby gaining weight, and wetting nappies and passing stools as expected.

Diagnosing low milk supply

Up to half of breastfeeding women worry their milk supply is low. A true low milk supply is uncommon, affecting only about 15% of mothers.

There is often an underlying cause which can be resolved. A proper assessment of breastfeeding technique and other maternal and infant factors to identify any potential cause, will lead to the most successful outcome, potentially without the need for medication.

Assessment tools are available and should be used by a suitable qualified person with skills in lactation support.

Some medicines may affect milk production. If you are concerned, check the Safety in Breastfeeding information, or contact the UK Drugs in Lactation Advisory Service (UKDILAS).

Medicines used to increase milk supply

Substances to increase milk supply are known as galactagogues.

No medicines are licensed in the UK for the treatment of low milk supply, and are therefore used off-licence. Follow the GMC’s guidance on unlicensed and off-licence prescribing.

Most galactagogues work by increasing prolactin levels. However, a higher prolactin level does not mean more milk. It is unknown if all women with a low milk supply also have low prolactin levels, and therefore if increasing prolactin levels further would help. A sudden increase in prolactin levels (usually triggered by nipple stimulation) seems to be important, not the maximum level produced. The frequent removal of milk via feeding also increases prolactin levels.

Evidence for the efficacy of galactagogues is limited, but they probably do increase milk volume initially. Prolactin levels also increase. We do not know if they help maintain breastfeeding long-term or increase infant weight gain.

Choice

If a galactagogue is required, domperidone is first choice due to most evidence for use and efficacy, better side-effect profile, and negligible passage into breast milk.

Other galactagogues include metoclopramide, sulpiride, and some herbal products. However, there is less evidence of efficacy, and these have other safety considerations.

Domperidone

Most evidence is in pre-term infants, which shows a moderate short-term effect on expressed breast milk volume, increasing by around 86 to 245mL per day. There is less evidence evaluating domperidone in mothers feeding term infants.

When to start

In studies, domperidone was started between days 1 and 33 post-delivery. It may be effective after this point, but there is no good evidence to support this.

Dose

Domperidone should be prescribed at a dose of 10mg three times daily. Doses higher than this should not be used.

Most studies used domperidone 10mg three times daily. Some small studies used higher doses. Only two small studies compared domperidone 10mg and 20mg three times daily. The 20mg groups produced on average slightly more milk, but it is uncertain whether this was a real difference or due to chance.

Domperidone does not always work. One study used domperidone 10mg and 20mg three times daily found a third of mothers did not have an increased milk supply at either dose. The study suggested that if there was no response to 10mg, increasing to 20mg was unlikely to work.

Duration of treatment

Domperidone should be prescribed for 7 days and then reviewed.

This is in line with the maximum treatment duration for the licensed indication (nausea and vomiting), due to the increased risk of cardiac events (particularly in certain populations), and potential for psychiatric withdrawal effects.

There is limited evidence regarding how long to use domperidone to increase milk supply. Some evidence shows the maximum effect is usually achieved within 7 to 14 days. Therefore, continuing treatment is unlikely to make a difference.

Whether to continue domperidone for longer than 7 days is a clinical decision after considering the evidence and potential increased risks.

Stopping treatment

Maintaining milk supply

It is not known whether stopping treatment with a galactagogue suddenly or gradually is better for maintaining milk supply. The American Academy of Breastfeeding Medicine recommends considering gradual discontinuation.

If milk supply reduces after stopping domperidone and improves on restarting again, gradually decrease to the lowest effective dose, and attempt discontinuation again.

Gradual withdrawal may also help reduce concerns about discontinuation.

Withdrawal symptoms

A small number of case reports suggest withdrawal symptoms occur when domperidone is discontinued either suddenly or gradually. In all cases, either prolonged use (up to 10 months) or higher than recommended doses (up to 160mg daily) were used.

Symptoms of withdrawal include insomnia, anxiety, headaches, palpitations, gastro-intestinal disturbances and depression. Re-emergence of previous mental health conditions has been reported.

If suspected withdrawal symptoms occur, increase the dose of domperidone back to a level that does not produce symptoms, and restart withdrawal more slowly.

A Canadian Safety Review on this issue is available.

Risk of cardiac events

Domperidone can cause a small increased risk of serious cardiac events, including certain types of arrhythmias, especially when used in high doses, for longer periods, or when additional risk factors are present. Patients at higher risk include those with cardiac disease, severe liver problems, electrolyte imbalances, or taking medicines affecting the QT interval or which interact with domperidone.

Maternal risk

Most breastfeeding women are relatively young and healthy and their baseline risk of cardiac events is very low.

A large cohort study involving over 1 million post-partum patients found domperidone increased the baseline ventricular tachycardia rate from 0.20 to 0.74 per 10,000 person years. It is not possible to prove whether the increase was due to chance or not. No sudden cardiac deaths in the domperidone group were reported, and the rate of all-cause mortality was decreased.

An increased incidence of arrhythmia in women with no arrhythmia history, taking domperidone to increase milk supply, has generally not been seen in studies.

Domperidone can be considered if a woman has no additional cardiac or medical risk factors, and is not taking medication that interacts with domperidone or affect the QT interval. Further information on drug-induced QT interval prolongation is available.

However, if risk factors are present, then ECG monitoring may be required, or an alternative considered. Contact UKDILAS for alternative galactagogue use.

Infant risk

Cardiac events in the infant have not been reported after domperidone exposure via breast milk.

In one study in premature infants, five babies had a prolonged QT interval, although none had symptoms or needed intervention. This was more likely due to infant prematurity than domperidone exposure.

If the infant has cardiac disease, severe liver disease or is receiving medicines which may be a problem, then domperidone use in the mother is best avoided. Contact UKDILAS for alternative galactagogue use.

Domperidone levels in breast milk

Very limited information shows domperidone passes into breast milk in negligible amounts (less than 0.5% of the maternal weight-adjusted dose), even with high dose, long term therapy.

In addition, there is a very low risk of accumulation in the infant and its low oral bioavailability will limit the amount absorbed from the breast milk.

Monitoring the infant

No serious side-effects have been reported in infants exposed to domperidone via breast milk.

As a precaution, monitor for gastro-intestinal disturbances, or signs of dry mouth, such as difficulty feeding.

Since there is no evidence that domperidone via breast milk can cause significant ECG changes in the infant, infant ECG monitoring is not routinely required. If there are additional risk factors, contact UKDILAS.

Ongoing support

Ongoing lactation support will be necessary during treatment with domperidone. Regular review is needed if domperidone is used beyond 7 days.

Induced or restarting lactation

Inducing lactation in a person who has not given birth, or restarting after a period of non-lactation, is beyond the scope of this article.

Contact us

Get in touch with the UK Drugs In Lactation Advisory Service if:

• you need further advice
• you are considering a different medicine for low milk supply
• multiple medicines are being taken

Acknowledgement

Thanks to Dr Louise Santhanam, General Practitioner, and Leicester Mammas CIC for their expert review.

Bibliography

A referenced version is available on request.